1. Expect Muscle Studies
ALS (amyotrophic lateral sclerosis) is a disease with symptoms that are so common to other disease processes that doctors often overlook it in the initial stages. Since there isn't one specific test that is conclusive to diagnose ALS, doctors often reach a diagnosis by assessing a compilation of symptoms and several different test results.
As symptoms such as muscle weakness, twitching and difficulty with speech progress, specialists will perform electrodiagnostics tests. One of these tests is an EMG (electromyography), which records the electrical activity of the muscle with the use of a hair-thin electrode inserted into the muscle. Comparative studies include the muscle at rest and the muscle in a contracted state. The EMG includes a nerve conduction study (NCS) to evaluate the response of nerve signals in the muscle.
2. Prepare for Neurological Imaging
Since the signs and symptoms of ALS mock those present in other disease processes or injuries, doctors will perform some type of imaging to rule out those possibilities. The most common imaging diagnostic procedures are a CT (computerized tomography) scan and an MRI (magnetic resonance imaging). The MRI and CT scan are safe and painless, and no special preparation is required.
3. Identify Abnormalities With Laboratory Testing
Doctors will perform a spinal tap (or lumbar puncture), not to diagnose ALS specifically, but to rule out other possible causes for the symptoms. During the procedure, you lie on your side and draw your your knees to your chest in a fetal position. A local anesthetic minimizes discomfort while the doctor inserts a needle into the spinal canal and withdraws a sample of fluid. This fluid undergoes a variety of laboratory tests, including glucose level, number and types of white blood cells and types of proteins.
Blood analysis and urine tests such as thyroid, 24-hour urine and high-resolution serum protein electrophoresis are other laboratory efforts that can narrow the list of possible diagnoses with symptoms similar to ALS. Looking at the lab results alone may be inconclusive, but when considered with the results of the complete battery of testing, these tests can provide invaluable information to obtain an accurate diagnosis.
4. Combine All Test Results for a Diagnosis
The results from all areas of diagnostic testing, along with a complete and thorough neurological examination and family history, give your physician the tools necessary to diagnose ALS. By the time most patients present identifiable symptoms, the disease process is well underway. There is no reversal or cure for amyotrophic lateral sclerosis, but early diagnosis allows for treatments that can slow the progression of symptoms and provide comfort measures while living with the disease.
